/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.controlcarappv2;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.Toast;

/**
 * This class does all the work for setting up and managing bluetooth
 * connections with other devices. It has a thread that listens for incoming
 * connections, a thread for connecting with a device, and a thread for
 * performing data transmissions when connected.
 */
public class BluetoothService {

	// Member fields
	private final BluetoothAdapter mAdapter;
	private final Handler meuHandler;
	private ConnectThread mConnectThread;
	private ConnectedThread mConnectedThread;
	private int mState;

	// Constants that indicate the current connection state
	public static final int STATE_NONE = 0; // we're doing nothing
	public static final int STATE_LISTEN = 1; // now listening for incoming
												// connections
	public static final int STATE_CONNECTING = 2; // now initiating an outgoing
													// connection
	public static final int STATE_CONNECTED = 3; // now connected to a remote
													// device

	/**
	 * Constructor. Prepares a new BluetoothChat session.
	 * 
	 * @param context
	 *            The UI Activity Context
	 * @param handler
	 *            A Handler to send messages back to the UI Activity
	 */
	public BluetoothService(Context context, Handler handler) {
		mAdapter = BluetoothAdapter.getDefaultAdapter();
		mState = STATE_NONE;
		meuHandler = handler;
	}

	/**
	 * Set the current state of the chat connection
	 * 
	 * @param state
	 *            An integer defining the current connection state
	 */
	private synchronized void setState(int state) {
		mState = state;

		// Give the new state to the Handler so the UI Activity can update
		meuHandler.obtainMessage(MainActivity.MESSAGE_STATE_CHANGE, state, -1)
				.sendToTarget();
	}

	/**
	 * Return the current connection state.
	 */
	public synchronized int getState() {
		return mState;
	}
	
	/**
	 * Start the ConnectThread to initiate a connection to a remote device.
	 * 
	 * @param device
	 *            The BluetoothDevice to connect
	 */
	public synchronized void connect(BluetoothDevice device) {

		// Cancela outra tentativa de conexao.
		if (mState == STATE_CONNECTING) {
			if (mConnectThread != null) {
				mConnectThread.cancel();
				mConnectThread = null;
			}
		}

		// Cancela outra conexao existente.
		if (mConnectedThread != null) {
			mConnectedThread.cancel();
			mConnectedThread = null;
		}
		
		// Inicia a nova conexao.
		mConnectThread = new ConnectThread(device);
		mConnectThread.start();
		setState(STATE_CONNECTED);
	}

	/**
	 * Start the ConnectedThread to begin managing a Bluetooth connection
	 * 
	 * @param socket
	 *            The BluetoothSocket on which the connection was made
	 * @param device
	 *            The BluetoothDevice that has been connected
	 */
	public synchronized void connected(BluetoothSocket socket,
			BluetoothDevice device) {

		// Cancel the thread that completed the connection
		if (mConnectThread != null) {
			mConnectThread.cancel();
			mConnectThread = null;
		}

		// Cancel any thread currently running a connection
		if (mConnectedThread != null) {
			mConnectedThread.cancel();
			mConnectedThread = null;
		}

		// Start the thread to manage the connection and perform transmissions
		mConnectedThread = new ConnectedThread(socket);
		mConnectedThread.start();

		// Send the name of the connected device back to the UI Activity
		Message msg = meuHandler.obtainMessage(MainActivity.MESSAGE_DEVICE_NAME);
		Bundle bundle = new Bundle();
		bundle.putString(MainActivity.DEVICE_NAME, device.getName());
		msg.setData(bundle);
		meuHandler.sendMessage(msg);

		setState(STATE_CONNECTED);
	}

	/**
	 * Stop all threads
	 */
	public synchronized void stop() {
		
		if (mConnectThread != null) {
			mConnectThread.cancel();
			mConnectThread = null;
		}
		if (mConnectedThread != null) {
			mConnectedThread.cancel();
			mConnectedThread = null;
		}
	
		setState(STATE_NONE);
	}

	/**
	 * Write to the ConnectedThread in an unsynchronized manner
	 * 
	 * @param out
	 *            The bytes to write
	 * @see ConnectedThread#write(byte[])
	 */
	public void write(byte[] out) {
		// Create temporary object
		ConnectedThread r;
		// Synchronize a copy of the ConnectedThread
		synchronized (this) {
			if (mState != STATE_CONNECTED)
				return;
			r = mConnectedThread;
		}
		// Perform the write unsynchronized
		r.write(out);
	}

	/**
	 * Indicate that the connection attempt failed and notify the UI Activity.
	 */
	private void connectionFailed(String erro) {
		setState(STATE_LISTEN);

		// Send a failure message back to the Activity
		Message msg = meuHandler.obtainMessage(MainActivity.MESSAGE_TOAST);
		Bundle bundle = new Bundle();
		bundle.putString(MainActivity.TOAST, "Erro ao Enviar" + erro);
		msg.setData(bundle);
		meuHandler.sendMessage(msg);
	}

	/**
	 * Indicate that the connection was lost and notify the UI Activity.
	 */
	private void connectionLost() {
		setState(STATE_LISTEN);

		// Send a failure message back to the Activity
		Message msg = meuHandler.obtainMessage(MainActivity.MESSAGE_TOAST);
		Bundle bundle = new Bundle();
		bundle.putString(MainActivity.TOAST, "Perca de conexao");
		msg.setData(bundle);
		meuHandler.sendMessage(msg);
	}
	
	/**
	 * This thread runs while attempting to make an outgoing connection with a
	 * device. It runs straight through; the connection either succeeds or
	 * fails.
	 */
	private class ConnectThread extends Thread {
		private final BluetoothSocket mmSocket;
		private final BluetoothDevice mmDevice;

		public ConnectThread(BluetoothDevice device) {
			mmDevice = device;
			BluetoothSocket tmp = null;

			// Get a BluetoothSocket for a connection with the
			// given BluetoothDevice
			try {
				Method m = mmDevice.getClass().getMethod("createRfcommSocket", new Class[] {int.class});
		         tmp = (BluetoothSocket) m.invoke(device, 1);
			} catch (Exception e) {
			}
			mmSocket = tmp;
		}

		public void run() {
			setName("ConnectThread");

			// Always cancel discovery because it will slow down a connection
			mAdapter.cancelDiscovery();

			// Make a connection to the BluetoothSocket
			try {
				// This is a blocking call and will only return on a
				// successful connection or an exception
				mmSocket.connect();
			} catch (IOException e) {
				connectionFailed(e.getMessage());
				// Close the socket
				try {
					mmSocket.close();
				} catch (IOException e2) {
				}
				// Start the service over to restart listening mode
				//BluetoothService.this.start();
				return;
			}

			// Reset the ConnectThread because we're done
			synchronized (BluetoothService.this) {
				mConnectThread = null;
			}

			// Start the connected thread
			connected(mmSocket, mmDevice);
		}

		public void cancel() {
			try {
				mmSocket.close();
			} catch (IOException e) {
			}
		}
	}

	/**
	 * This thread runs during a connection with a remote device. It handles all
	 * incoming and outgoing transmissions.
	 */
	private class ConnectedThread extends Thread {
		private final BluetoothSocket mmSocket;
		private final InputStream mmInStream;
		private final OutputStream mmOutStream;

		public ConnectedThread(BluetoothSocket socket) {
			mmSocket = socket;
			InputStream tmpIn = null;
			OutputStream tmpOut = null;

			// Get the BluetoothSocket input and output streams
			try {
				tmpIn = socket.getInputStream();
				tmpOut = socket.getOutputStream();
			} catch (IOException e) {
			}

			mmInStream = tmpIn;
			mmOutStream = tmpOut;
		}

		public void run() {
			byte[] buffer = new byte[1024];
			int bytes;

			// Keep listening to the InputStream while connected
			while (true) {
				try {
					// Read from the InputStream
					bytes = mmInStream.read(buffer);

					// Send the obtained bytes to the UI Activity
					meuHandler.obtainMessage(MainActivity.MESSAGE_READ, bytes,
							-1, buffer).sendToTarget();
				} catch (IOException e) {
					connectionLost();
					break;
				}
			}
		}

		/**
		 * Write to the connected OutStream.
		 * 
		 * @param buffer
		 *            The bytes to write
		 */
		public void write(byte[] buffer) {
			try {
				mmOutStream.write(buffer);

				// Share the sent message back to the UI Activity
				meuHandler.obtainMessage(MainActivity.MESSAGE_WRITE, -1, -1,
						buffer).sendToTarget();
			} catch (IOException e) {
				Toast.makeText(null, e.getMessage(), Toast.LENGTH_SHORT).show();
			}
		}

		public void cancel() {
			try {
				mmSocket.close();
			} catch (IOException e) {
			}
		}
	}
}
